Cellulose derivative based biodegradable support structures for 3D printing

Abstract

The present disclosure relates to support structures for three dimensional (3D) printing, methods of preparing the support structures, and methods of using the support structures. In particular, the support structures comprise a hydrogel comprised of a cellulose derivative. Preferably, the support structures are biodegradable and easily removed without generating toxic waste.

What is claimed is: 
     
       1. A method of forming a three-dimensional object, the method comprising:
 printing a support structure from a support material, wherein the support material comprises a hydrogel of a cellulose derivative, wherein the cellulose derivative comprises hydroxypropyl methylcellulose. 
 
     
     
       2. The method of  claim 1 , wherein the support structure is biodegradable. 
     
     
       3. The method of  claim 1 , wherein the hydrogel is removable by dissolving in water. 
     
     
       4. The method of  claim 1 , wherein the hydrogel comprises from about 8% w/v to about 12% w/v of the cellulose derivative. 
     
     
       5. The method of  claim 1 , wherein the degree of substitution of hydroxyl groups of the cellulose derivative is from about 20% to about 50%. 
     
     
       6. The method of  claim 1 , further comprising:
 printing a main structure from a build material on the support structure; and 
 removing the main structure from the support structure. 
 
     
     
       7. The method of  claim 6 , wherein the removing comprises contacting the support structure with water. 
     
     
       8. The method of  claim 7 , wherein the water is at a temperature of about 20° C. 
     
     
       9. The method of  claim 6 , wherein the removing does not generate toxic waste or hazardous fumes. 
     
     
       10. The method of  claim 1 , wherein the printing comprises use of fused deposition modeling or material extrusion. 
     
     
       11. The method of  claim 1 , wherein the printing comprises dispensing the support material through a nozzle, and wherein the nozzle has a diameter of from about 0.4 mm to about 1.0 mm. 
     
     
       12. The method of  claim 1 , wherein the hydrogel is prepared by a method comprising:
 mixing the cellulose derivative with water to form a cellulose derivative mixture; 
 heating the mixture to about 70° C.; and 
 cooling the mixture to about 25° C. 
 
     
     
       13. A three-dimensional object comprising:
 a support structure formed from a support material, wherein the support material comprises a hydrogel of a cellulose derivative, wherein the cellulose derivative comprises hydroxypropyl methylcellulose; and wherein the hydrogel comprises from about 8% w/v to about 12% w/v of the cellulose derivative. 
 
     
     
       14. The three-dimensional object of  claim 13 , wherein the support structure is biodegradable. 
     
     
       15. The three-dimensional object of  claim 13 , wherein the cellulose derivative is water-soluble. 
     
     
       16. The three-dimensional object of  claim 13 , wherein the degree of substitution of hydroxyl groups of the cellulose derivative is from about 20% to about 50%. 
     
     
       17. The three-dimensional object of  claim 13 , further comprising a main structure, wherein the main structure is removable from support structure by contacting the support structure with water. 
     
     
       18. The three-dimensional object of  claim 17 , wherein the removal does not generate toxic waste or hazardous fumes.